[Pdns-users] PDNS Recursor Alpha - RAM usage

[Chris]

Hi all,

I have been running the alpha of PowerDNS recursor 
(4.0.0~alpha2-1pdns.jessie) for a while but seem to be having issues 
with the memory usage of it after a while.

My DNS servers all have 16GB of RAM, about 40% of which is allocated to 
MySQL (3 instances of PowerDNS auth running against 3 reasonably sized 
DB's), 10% which is taken up by everything else except PowerDNS recursor.

After about 2-3 weeks of running the memory usage of pdns recursor 
slowly creeps up until it is using all the memory + swap causing 
oomkiller to kill things off. This isn't really a problem as I use a 
health checker on each DNS server to verify everything works before 
announcing the IP's via BGP, but it would be nice if it just ran 
correctly without it restarting the rescursor so often. I have checked 
manually when monitoring starts alarming about the memory usage and by 
that time the recursor is using about 9GB of RAM + 4GB swap.

Here is the settings in my recursor.conf:

allow-from-file=/etc/powerdns/recursor_allowed_ips
api-key=...
api-readonly=no
carbon-ourname=dns1-recursor
carbon-server=...
daemon=yes
entropy-source=/dev/urandom
export-etc-hosts=off
forward-zones-file=/etc/powerdns/recursor_forward_zones
hint-file=/etc/powerdns/named.cache
local-address=10.254.1.10 10.254.1.11 fd12:3456:ffff:1::1 
fd12:3456:ffff:1::2
local-port=53
max-cache-entries=1000000
max-mthreads=8192
max-negative-ttl=360
max-qperq=100
max-tcp-clients=2048
max-total-msec=600000
network-timeout=3000
pdns-distributes-queries=yes
query-local-address=0.0.0.0
query-local-address6=::
setgid=pdns
setuid=pdns
threads=24
version-string=PowerDNS Recursor
webserver-address=...
webserver-allow-from=0.0.0.0/0,::/0
webserver-password=...
webserver-port=5333
webserver=yes

I have it reporting to a metronome instance I run myself and the memory 
used graph is a constantly increasing curve but I am not exactly sure 
why.... maybe I will need to reduce the max-cache-entries to something 
much lower?

Is anyone else having difficulties running recursor? What does your 
config look like/how much RAM does it use?

Thanks